BY LOREN CORDAIN, PH.D., PROFESSOR EMERITUS, FOUNDER OF THE PALEO DIET
APRIL 18, 2012

Body Mass Index (BMI), officially called the Quetelet Body Mass Index after its creator, Belgian mathematician Lambert Quetelet (1796-1874), is an easy way to estimate if you are overweight or obese. (Roughly two-thirds of adult Americans have BMI values that put them into one of these categories.) The breakdowns are as follows:

Underweight = less than 18.5

Normal = 18.5-24.9

Overweight = 25-29.9

Obese = 30.0 or greater

Across a large population, the BMI correlates well with degree of body fat. However, there are certain exceptions. Very muscular, heavy athletes, who are actually quite lean when their body fat is measured, may have high BMI values. And in older adults, BMI frequently underestimates a person’s amount of body fat.

If you have a BMI in the overweight or obese category, you have a significantly increased risk for cardiovascular disease, type 2 diabetes, the metabolic syndrome, and various cancers.

BMI is determined by dividing your weight in kilograms by your height squared in meters. The NIH has created a simple BMI calculator that you can find at: https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm